A portable electronic device includes: a display unit that displays a variety of information; and an operation unit that is configured with a plurality of keys.
Here, in a portable electronic device such as a cellular telephone device, an initial screen is displayed on a display unit while waiting for an incoming call or while waiting for activation of other applications. When an operation key assigned with a numeric character is depressed in this initial state, a numeric character corresponding to the operation key thus depressed is displayed on the display unit. In addition, in the cellular telephone device, for example, in a case in which an off-hook key is depressed in a state where numeric characters are displayed on the display unit, processing of an outgoing telephone call is performed based on the numeric characters that have been input, and in a case in which a key for activating a calculator (desk calculator) is depressed, a calculator application is activated with the numeric characters that have been input as an initial numeric value.
Moreover, a technique is proposed for a portable electronic device (for example, see Patent Document 1), in which, when a key operation is performed from an initial screen, a character corresponding to the key operation is displayed on a display unit, and when a predetermined operation (operation of depressing a key for displaying a list of applications) is performed, the list of applications corresponding to a displayed character string is displayed, and one application is selected from the list to activate the application.
Patent Document 1: Japanese Unexamined Patent Application, Publication No. 2007-200243